Vacuum ports question
 

I noticed that I have two vacuum ports disconnected;
one on top of the left carburettor (while the ones on the other three are plugged with a rubber cap), and one on the cylinder head next to the left carb, as seen in this picture;
http://www.xs4all.nl/~witholt/Mijn%2...m%20pijpje.jpg
I already found out that the engine idles a little higher and smoother when I block either one of them, and even slightly more when I block them off both.

So what should I do with these two ports?
Plug them both, or just the one on the carb, or are they supposed to be connected maybe?
I have no idea what they're for, so don't shoot me please :icon_teeth:

the ports on the cylinder head should all be capped. they are for balancing the carbs (syncing the carbs) and would definatly impact performance and fuel mixture. the ones on the carbs should be connected to something or capped...open vacuum ports are never good.

Allright, thanks :)
Will cap them both.